We employ a five-step risk scale with values ranging from "very low" to "very high" within six categories: Acute toxicity, Long-term toxicity, Dependence, Cognitive problems, Unpleasant events, and Interactions.
These values are based on qualitative reviews of available knowledge, and should only be viewed as guidelines. They are also relative, so a score of "very low risk" does not mean the substance is risk-free. The scale assumes users are normal, healthy individuals; beware that even drugs which are well-tolerated by most people may nevertheless be harmful to some users. It also assumes normal use patterns; that is, if a given drug is only harmful when used in a certain way, yet is almost never used in that way, then the drug will be considered less harmful compared to a similar drug which is commonly used in a harmful way.
⦿⦿⦿⦾⦾ (Moderate risk)
The difference between a recreational and a hypnotic (sleep-inducing) dose of GHB is very small. Although the vast majority of GHB-related deaths are due to combinations with other drugs, there are reports of lethal overdoses from GHB alone [17,23]. Oral doses of 100 mg GHB per kg of body mass, as well as intravenous doses of 70 mg/kg, have been administered without any negative effect on vital functions; early tests of GHB's anaesthetic potential evidently involved intravenous administration of up to 140 mg/kg [16,20–22].
Although the cause of death in lethal overdoses is respiratory failure, GHB actually has a minimal effect on respiration at medically relevant doses, hence its initial use as an anaesthetic [15,19,22]. GHB causes one to breathe more deeply, so that oxygen uptake is maintained even though one is breathing slower [8,15,16]. In animal experiments, this mechanism is observed all the way up to a lethal dose with GHB alone, but quickly fails when combined with alcohol in both animals and humans [9,11,24]. The risk of respiratory failure due to overdose may be affected by usage patterns: chronic GHB users develop a considerable tolerance to the recreational and hypnotic effects, but not to the antirespiratory effect . This means that heavy users who require higher doses to achieve their desired effect are at greater risk of harmful or lethal overdoses .
A GHB overdose commonly leads to users abruptly falling asleep, after which it is impossible to wake them up for the first couple of hours. Although the sleep itself is temporary, and even though they are breathing well, they may still suffocate to death if their breathing is somehow obstructed. There is also a serious risk of users choking to death on their vomit if they lie on their back during a GHB overdose, since it is not uncommon to vomit from too much GHB, especially in combination with alcohol [21,24]. For this reason, anyone who has fallen asleep after taking too much GHB must be placed in the recovery position and monitored closely to ensure they continue breathing. If there is any doubt about whether they have also consumed alcohol or other depressants in addition to GHB, or if they begin to breathe slower than eight times per minute, call an ambulance right away.
GHB overdoses are normally not treated with any antidotes, and most cases do not require intubation or mechanical ventilation, even with concomitant use of other drugs . However, monocarboxylate-transport-inhibitors (MCTi's) like diclofenac have been used to reverse GHB's effects in animal experiments, and the central nervous system (CNS) stimulant doxapram has been used to counteract the CNS depressant effects of GHB in at least one comatose patient [9,12,13]. In some drug use environments, amphetamine is used to wake people out of GHB overdoses, but this is risky from a medical perspective . LONG-TERM TOXICITY
⦿⦿⦾⦾⦾ (Low risk)
GHB occurs naturally in the human body and is not especially toxic to its organs. Animal experiments involving rats have nevertheless shown neurotoxic effects upon administration of low doses over a long time, but this effect is not seen in high doses, and it is unclear whether the results apply to humans. GBL and 1,4-butanediol appear to also have low toxicity to the body's organs, even though 1,4-butanediol does produce some harmful yet short-lived metabolites. GHB obtained illegally can, however, contain traces of caustic lye (sodium hydroxide) left over from the manufacture process, which can cause chemical burns. Products containing GBL or 1,4-butanediol may also contain other chemicals, which carry their own risks. DEPENDENCE
⦿⦿⦿⦾⦾ (Moderate risk)
Compared to to alcohol, GHB has a less severe hangover, improves sleep rather than worsening it, and is less toxic to the body. Because of this, it can be tempting to frequently take GHB instead of alcohol. However, frequent use of GHB can lead to withdrawal symptoms similar to those of alcohol dependence. Mild withdrawal is marked by irritability, anxiety, insomnia, and tremors, while more severe withdrawals may include psychoses and epileptic seizures. Going "cold turkey", i.e. abruptly quitting GHB after frequent heavy use, can lead to a medical or psychiatric emergency. This is why it is crucial to gradually step down from a heavy use pattern or dependence on GHB if one wishes to quit. In severe cases, withdrawal symptoms may need to be treated with baclofen and benzodiazepines as part of a drug replacement therapy program . COGNITIVE PROBLEMS
⦿⦿⦾⦾⦾ (Low risk)
A series of studies found that using GHB as a hypnotic (sleep-inducing drug) is associated with improved cognitive function . Although this is largely attributed to GHB's effect on sleep quality, which is known to greatly affect cognitive function, it also indicates that GHB does not have any significant negative effects on cognition . Crucially, however, these studies involved administering GHB twice per night. Taking only a single dose, meanwhile, can paradoxically worsen
overall sleep dividends: although sleep quality is improved, sleep duration may be reduced due to the sedative effects of GHB giving way to stimulation after only a few hours. This ultimately leads to lack of sleep, which does impair cognitive function over time.
Non-lethal GHB overdoses can indirectly lead to cumulative brain damage as a result of bodily organs being deprived of oxygen while sedated, mainly due to partially obstructed airways or simultaneous use of other CNS depressants. UNDESIRABLE EVENTS
⦿⦿⦿⦿⦿ (Very high risk)
As mentioned, an overdose of GHB can lead to users abruptly falling asleep for 2-3 hours, during which time they cannot be woken up. This means GHB use carries a major risk of being subjected to sexual assault, robbery, or other forms of exploitation. It also means that activities involving cold weather or bathing carry a serious risk of hypothermia or drowning. You should therefore never use GHB in unsafe places or with people you do not know or trust, and there should always be someone nearby who can watch over you in case you fall asleep.
GHB inhibits impulse control and can thus lead to boundary-breaking behavior, especially in combination with other drugs. Stimulants in particular can counteract the hypnotic effect and enhance the stimulating effect of GHB, causing one to remain awake and able to do things even after taking too much GHB. However, users commonly report feeling more clear-headed on GHB than they do on alcohol, and someone under the effects of GHB may be mentally present despite almost falling asleep.
At higher doses, GHB interferes with motor skills and coordination, leading to a higher risk of accidents in situations where bodily control and balance are needed.
GHB can trigger seizures in people diagnosed with epilepsy, and is therefore contraindicated for use as a sleep aid in this cohort. INTERACTIONS
⦿⦿⦿⦿⦿ (Very high risk)
Combining GHB with alcohol, opioids, or other CNS depressants/sedatives greatly increases the risk of overdosing on GHB, as well as increasing the risk of respiratory arrest and brain damage in case of an overdose [18,11]. If someone is unconscious and you suspect they may have taken another depressant (e.g. alcohol, benzodiazepines or opioids) in addition to GHB, call an ambulance immediately
CNS stimulants counteract the depressant effects of GHB until the stimulant wears off. This can lead to situations where someone on stimulants ends up taking more GHB than they could safely handle if they were not on a stimulant, only to later suffer an overdose reaction once the stimulant wears off and the full effect of the GHB dose kicks in. This risk is especially high for simultaneous use of GHB and short-acting stimulants like cocaine or mephedrone, but also when taking GHB towards the end of the stimulant high with the goal of softening the come-down.
Interactions between GHB and other legal medications, see Felleskatalogen
. Note that GBL and 1,4-butanediol may have additional interactions not listed for GHB, as these are metabolized into GHB by enzymes that are not involved in the metabolism of GHB. These interactions have not yet been fully documented.